1. Technical Field
The present invention relates to developing devices, image forming apparatuses, and image forming systems.
2. Related Art
Image forming apparatuses such as laser beam printers are well known. Such image forming apparatuses include, for example, an image bearing member that bears a latent image, and a developing device that develops the latent image borne on the image bearing member using toner. In the case where an image signal or the like is sent from an external device such as a computer, the image forming apparatus forms a toner image on the image bearing member by developing the latent image borne on the image bearing member using the developing device. Then, the image forming apparatus transfers the toner image to a medium and finally the image is formed on the medium.
The developing device is provided with a toner bearing member that bears toner and develops the latent image borne on the image bearing member using toner, and a regulation member that comes into contact with a contact section on a surface of the toner bearing member to regulate an amount of toner borne on that surface. The toner bearing member is provided with projecting sections that are arranged in a regular manner on its surface, and bears toner on the projecting sections and in portions of its surface other than the projecting sections. The regulation member is arranged so that a longitudinal direction of the regulation member runs along an axial direction of the toner bearing member, and so that a leading edge of the regulation member in a lateral direction and a thickness direction faces an upstream side of the toner bearing member in a rotating direction. In this developing device, after the toner borne on the toner bearing member is regulated by the regulation member, the toner is supplied for the development of the latent image on the image bearing member.    Patent document 1: JP-A-2006-259384    Patent document 2: JP-A-2003-57940
By the way, there are cases where a toner having a slow charging rise (toner that takes time for its charging amount to reach a saturated charge amount) is used as the toner in this image forming apparatus. And a phenomenon called development memory can occur due to the slowness of the charging rise when the latent image is to be developed using this toner. And occurrences of this phenomenon are a cause of deterioration of image quality in images.
Accordingly, to inhibit the aforementioned development memory, a system is conceivable in which the latent image is developed using toner borne on portions other than the projecting sections on the surface of the toner bearing member. And this system is achievable by bringing the regulation member into contact with the toner bearing member so that a distance between the leading edge and the projecting sections in the case where the leading edge of the regulation member faces the projecting sections of the toner bearing member is smaller than a volume mean particle size of the toner.
However, in regard to the above description, it becomes difficult for the toner to be borne on the projecting sections, and the contact section of the regulation member may come into direct contact with the projecting sections without toner interposed therebetween. In the case where the contact section comes into direct contact with the projecting sections, the contact section adheres closely to the projecting sections undesirably, and due to this, problems such as unusual sounds may occur between the toner bearing member and the contact section during rotation.